Electric lamp



Dec. 18, 1934. H. A. DOUGLAS 1,985,024

A ELECTRIC LAMP Filed Oct. 23, 1929 2 Sheets-Sheet 2 of the lamp base. The body of the reflector, the holder 9, and the socket 12 are grounded and when the lamp is in place the sheath 27 is also grounded as it has connection with the holder, as will more fully appear. I

The cross section of the socket 12 is smaller than the bore of the holder 9 and the base of the lamp, inclusive of its sheath 27, is smaller, in cross section, than the bore of the socket.

Spaced apart spacing means intervene between the holder 9 and the socket 12. These spacing means are preferably in vthe form of ribs 28 which extend along the holder and socket. Each rib is desirably integrally formed with one of the elements 9 or 12, both ribs being shown as being integrally formed with the holder. The ribs are spaced less than 180 degrees apart, preferably 120 degrees apart. The means for pressing the socket 12 against the holder 9 is desirably inclusive of two spring tongues' 29A which are integrally formed Vwith the holder 9. These springs are arrangedin spaced apart pairs, the springs of each pair being also spaced apart. The socket 12 is formed with lugs 30 pressed outwardly therefrom. Each lug is snugly received between two corresponding springs of a pair, whereby the vsocket is prevented from having longitudinal movement. By this preferred construction, it is unnecessary to specially design the reflector as would be desirable if the lamp socket ywere movable along the lamp axis. rI'he springs 29'engage the adjacent side of the socket and press the opposite side of the socket evenly againstthe ribs 28, the line of pressure being between these ribs. In this way, the axis of the socket is xed with respect to the reflector.

The bayonet channels are spaced lessy than 180 degrees apart and the bayonet projections are correspondingly spaced. The bayonet channels are similarly, instead of symmetrically related. At least one side of each bayonet seat extends along, as distinguished from crosswise, of the socket axis and is oblique to such axis. As here shown, each bayonet seat has a similar surface 13" whichl surfaces 13' are of the same length and are inclined upwardly and forwardly at the rsame angle. These sloping seat sides are Vpressed upon by the bayonet projections laterally of the socket to press the lamp baselaterally of the socket away from these sloping seat sides and against the socket. The spaced apart spacing ribs 31, which extend along the socket and lamp base are located at the side of the socket toward which vthe lamp base is pressed. Both sloping surfaces 13 are of suflicient length, so that the ribs 31 engage the side of the socket before the bayonet pins reach the upper ends of the slopes .13. cooperate importantly to accomplish the wedging action desired tosecurev a tight assembly of the lamp and socket and to cause the axis of the lamp to be coincident or parallel to the axis of the socket.y

It will be seen that the socket and lamp are, by means of the device of my invention, in

Vfixed relation with each other and with the socket holder and the reflector which carries Thus the slopes 13 and ribs 31 the socket holder and, through the intermediation of these elements, with the filament 25 so that this filament is maintained in a predetermined denite relation to the reflector. In the embodiment of the invention illustrated, the filament is upon the axis of the reflector, which is preferably parabolic. The lamps which are designed for use in this structure are manufactured with all filaments in the same relative positions to the lamp bases'and as the lamps are in this respect similar and in other respects also, they maybe readily replaced with the assurance that the lament will come exactly into the right position with respect to the reector when any lamp is inserted within its socket.

Changes maybe made without departing from the invention.4

Having thus described my invention, I claim:

1. In an electric lamp, the combination of an incandescent lamp bulb having a generally cylindrical base; spacing ribs spaced apart less than 180 degrees projectingradiallyvfrom the base and extending longitudinally thereof in parallel relationship; two bayonet pins spaced apart less than 186 degrees on the base, the spacing ribs being located at one side of the base between both bayonet pins with each rib at an equal distance from the adjacent pin; a cylindrical lamp socket receiving said base; bayonet slots in the socket receiving the bayonet pins; bayonet seats in said bayonet slots, said seats having similar parallel sloping sides oblique to the axis of the socket and directed forwardly of the socket and toward the side ofthe socket receiving said spacing ribs, said bayonet pins and sloping sides being less than one hundred eighty degrees apart and upon the opposite side of the axis of said lampbase from said ribs and a spring carried at the rear of the socket and pressing the lamp base forwardly of the socket and the bayonet pins' along said sloping sides to press the spacing ribsv laterally against the wall of the socket before the bayonet pins reach the ends of thev sloping bayonet seat sides;

2. In an electric lamp, the combination with an incandescent lamp bulb having a'I generally cylindrical base and two bayonet projections spaced apart less than 180 degrees on the base; of a cylindrical socket receiving said base; two bayonet slots in the socket receiving the bayonet projections therethrough; bayonet seats at the inner end of the slots receiving the bayonet projections upon a turning movement ofr the lamp base in the socket, a similar gradually sloping side in each bayonet seat contacting each bayonet projection and directed forwardly ofthe socket and toward a side thereof at substantially the same angle; and a spring carried at the rear of the socket and pressing the larnp base forwardly to cam the bayonet projections in the same direction toward one side of the socket whereby the lamp base is wedged against said side of the socket, said similar sloping sides of the bayonet seats being Ofsuicient length so that the lamp base contacts the side of the` socket before the bayonet projections reach the forward ends of the .said sloping sides.

HARRY A. DOUGLAS. 

